I’ve often said that I think Photoshop is the missing link in most learning developers’ tool sets. Photoshop allows you to create almost any type of image using digital drawing, painting, and (of course) photography tools in a single digital environment.
When it comes to removing backgrounds in photos, how you approach removal is more a factor of the type of image you’re working with than anything else. Some types of images—often those with a high level of contrast—are fairly easy to move (Figures 1 and 2).
Figure 1: Images like these facilitate easily removing backgrounds. This ship could easily be removed from the water and placed in another image.
Figure 2: Removing the background would be much more difficult with this image due to the wispy strands of hair and the lack of contrast between the hair and the background color
Removing geometrical objects from background
When you want to remove an object with a recognizable geometric shape, your job will be fairly easy, as there are several tools within Photoshop that will facilitate this task.
Inside your Photoshop tool palette, there are two sets of tools that you can use to make geometrical selections. Let’s start with the two marquee tools (Figure 3).
Figure 3: This is the first of two sets of tools that you can use to make geometrical selections. The marquee tools facilitate selecting areas within an image.
The Rectangular Marquee tool allows you to select any rectangular area within the image. Similarly, the Elliptical Marquee tool allows you to select any elliptical or circular area within the image.
For example, in the image below (Figure 4), I used the Elliptical Marquee tool to select the cut half-orange. Once you select a part of an image, you will see the “marching ants” surround the selected portion of the image. You can also enter Quick Mask mode (Q key) (Figure 5) to more easily see exactly what is selected.
Figure 4: A selection made using the Elliptical Marquee tool
Figure 5: The same image in Quick Mask mode
Once you exit Quick Mask mode, to remove the background you can use the Inverse option under the Select drop-down menu. This will reverse the selection so that everything but the cut orange is selected. Now, assuming the layer with the image is still selected in your Layers panel, simply press the delete key on your keyboard and the selected area will disappear (Figure 6).
Figure 6: We’ve successfully removed the rest of the image, leaving only the perfectly round orange slice
Obviously, most images are more complex than our orange image. If there are still discernable geometric shapes, we can use the Polygonal Lasso tool or the Magnetic Lasso tool to facilitate removing the background (Figure 7). The Polygonal Lasso tool allows you to select any polygon. The Magnetic Lasso attempts to sense what you are trying to remove and attaches the selection to a border it can find.
Figure 7: The lasso tools facilitate selecting more complex geometrical shapes
The church in the image below (Figure 8) is a perfect candidate for the Polygonal Lasso tool. There are distinct polygons here.
Figure 8: Due to the distinct geometric shape of this church building, the Polygonal Lasso tool would be the best choice to remove it from the background
To use the Polygonal Lasso tool, select it from the toolbox, and then click on each corner of the building. You’ll see lines appear tracking the sides of the building. When you’ve clicked on all the corners, click where you started to close the selection (Figure 9). Again, you can use Quick Mask mode to verify your selection.
Figure 9: A nice, tight selection made using the Polygonal Lasso tool
Again, inverse the selection, and press delete to free the church from the background (Figure 10). Once the background is eliminated, you are free to compose a new image appropriate for your learning content.
Figure 10: Mission accomplished. The background is removed while the church is preserved.
For more complex removals, I like using the Magic Wand tool and the Quick Selection tool (Figure 11). These tools work based on color differential, looking for areas of contrast within the image.
Figure 11: The Quick Selection and Magic Wand tools work based on color differentials, rather than shapes or areas
These tools are good candidates to use with images where the part you want to select is not geometrical. The Quick Selection tool would work well with the image below (Figure 12).
Figure 12: If we wanted to use this man in a slide, but not the background, the Quick Selection tool would be a good choice to remove the background
With the Quick Selection tool, drag over the man. You can also click in areas that are tighter, and you’ll see a selection marquee gradually cover the man. You’ll notice that, due to contrast with the background, the selection is fairly easy to make. Quick Mask mode will allow you to quickly verify your selection (Figure 13).
Figure 13: Another nice, tight selection made!
Once you remove the man from the original image, you can be creative and create a composite image that is appropriate for your learning content. In the example below (Figure 14), we used a new background and simple typographical treatment to create a cover slide for learning content.
Figure 14: What a difference background makes. Using black-and-white photography with the color image of the man provides a nice contrast.
Now let’s turn to a more difficult selection.
Figure 15: Selecting the man in this image is more difficult for several reasons. The image is lower resolution, his hair blends into the background, and there’s less contrast overall.
With this image, first, using whatever combination of tools you think best, make the best selection you can (Figure 15). Switching in and out of Quick Mask mode can be especially helpful here as you try to make a strong selection (Figure 16).
Figure 16: You’ll notice that the hair on the top of his head is not selected, as some of the wispier areas were missed by the selection tools
In Quick Mask mode, you can use the paint tool and paint in the wispy areas of hair. When you’re painting the color, black will add to the mask (selection) and the color white will erase selected areas. You should zoom in very tight for this and keep switching out of Quick Mask mode to see your work (Figure 17).
Figure 17: Painting in some of the hair on top of the man’s head
Once you have made a selection you’re happy with, you can remove the man and composite him in any appropriate image for your learning content (Figure 18).
Figure 18: We meet our friend again—wispy hairs and all!
This is a process for the patient person. It takes time and effort to get this right, but, once you do, you can make beautiful selections on almost any object in Photoshop.